This invention relates to the art of ink cartridges for ink jet printers and, more particularly, to arrangements for relieving the strain on an ink supply line to an ink cartridge in a continuous ink supply system.
Continuous ink refill systems for disposable ink jet cartridges are well known as shown, for example, in U.S. Pat. No. 5,469,201 to Erickson, et al. and U.S. Pat. No. 5,745,137 to Scheffelin, et al., both of which are incorporated herein by reference for background information. Basically, in such a continuous ink refill system, a cartridge is connected to an auxiliary ink supply reservoir by means of a flexible hose or tube, and during operation of the printing system, the tube is open to allow ink to flow from the auxiliary reservoir to the ink cartridge. During shipment or handling of the ink supply reservoir/cartridge system when it is outside the printer, as well as during the installation and removal of the system relative to a printer, it is important that the connection of the supply tube to the cartridge be leak tight to preclude the leakage of ink within the cartridge assembly, onto exterior surfaces of the cartridge, into a container in which the ink supply reservoir system is packaged, and/or onto surfaces within the printer. In connection with maintaining a leak tight connection for the latter purposes, it is important to optimize protection of the supply tubing from becoming disconnected from the cartridge during use and/or handling.
Heretofore, as shown for example in the aforementioned patent to Erickson, et al., the ink supply tube extends into a cartridge through an opening in a wall thereof and the tubing is bonded to the cartridge at the opening to provide strain relief against separation of the tubing from the cartridge. In the patent to Scheffelin, et al., the supply tubing is coupled to the cartridge through the cartridge handle and a slidably interengaged coupling arrangement. Neither of these arrangements secures the tubing relative to the cartridge so as to preclude the direct application of force axially of the tubing which can result in separation thereof from the cartridge and, accordingly, neither arrangement provides an adequate relief of or protection against strain on the tubing at the point of connection with the cartridge.